Visual Information Apparatus for Real-Time Demonstration of Braking Behaviour of Motorcycles

ABSTRACT

Visual information apparatus for real-time demonstration of braking behaviour of a motorcycle, the motorcycle is provided with elastically suspended front wheel and rear wheel ( 3,4 ), independently operable front wheel brake and independently operable rear wheel brake and a visual display device ( 7 ). The apparatus is provided with sensors ( 5,6 ) adapted to measure directly or indirectly the momentary forces acting on said elastic suspensions ( 1,2 ) of the front wheel and rear wheel ( 3,4 ) respectively, or to measure indirectly the ratio of said forces; a calculating means adapted to calculate from the signals of said sensors ( 5,6 ) the ratio of said momentary forces acting on said suspensions ( 1,2 ) of said front and rear wheel ( 3,4 ) and to calculate the difference between said ratio and a given value. The visual display device ( 7 ) is adapted to display the deviation.

The present invention relates to a visual information apparatus forreal-time demonstration of braking behaviour of a motorcycle, themotorcycle is provided with elastically suspended front wheel and rearwheel, independently operable front wheel brake and independentlyoperable rear wheel brake and a visual display device.

When driving a motorcycle proper and synchronized control of the brakes(front brake and rear brake operated independently of each other bymeans of a brake lever and/or brake pedal) and the driving force appliedto the rear wheel (throttle lever) is very important. Otherwise themotorcycle might overturn either in the forward direction or backwarddirection which might be fatal to the driver.

In order to make the behaviour of a running motorcycle controllable onthe basis of measuring parameters during its running state severalattempts have been made. Patent application FR2720992 (Honda Motor Co.Ltd.) describes a brake system for motorcycles. The system consists ofbrake levers connected to the front and rear brakes by mechanicaloperating cables transmitting force to the front wheel brake and therear wheel brake. A locking mechanism intercepts the force transmittedand when the brake force on one of the wheels exceeds a certain levelthe locking mechanism blocks or increases the mechanical forcetransmitted to the other wheel.

The object of U.S. Pat. No. 6,409,285 (also owned by Honda Motor Co.Ltd.) is to provide a front wheel and rear wheel interlocking brakesystem having a simple structure, which is capable of automaticallyperforming brake control of the front and rear wheels on the basis ofthe running state of the motorcycle. The brake system includes a frontwheel side actuator and a rear wheel side actuator for applying pressureto the respective wheel brake. At least one operating member is operatedby a driver. An operated amount detecting member is provided fordetecting the operated amounts of each brake operating member. A controlmember is provided for receiving and calculating each of operatedamounts detected and outputting drive control signals on the basis ofthe calculated result. The control member performs brake control inaccordance with specific braking force distribution characteristics(FIGS. 4, 6-8) which were fined probably on the basis of practicalexperiences, tests.

Both solutions imply automatic intervention and do not count on thedriver. This, however, demands numbersome technical measures to be takenduring manufacture which are necessary for appropriate modification ofthe structure. It is expensive and only the manufacturer is able toperform it safely. Disassembly and subsequent conversion of motorcyclesis difficult and hazardous especially when the braking system isconcerned.

The object of the present invention is to provide a solution by whichdisassembly of the braking system can be omitted and there is no needfor intervention in the control system of the brakes.

Another object is to provide information to the driver on the basis ofwhich the driver is able to make a decision as a result of which theamount or the ratio of the braking force applied to the front wheelbrake and rear wheel brake can be influenced.

A further object is to support learning to drive a motorcycle byproviding a device by means of which the driver's skill can be improved.

To achieve the above objects there is provided an apparatus havingsensors adapted to measure directly or indirectly the momentary forcesacting on the elastic suspensions of the front wheel and rear wheelrespectively, or to measure indirectly the ratio of these forces; acalculating means adapted to calculate from the signals of the sensorsthe ratio of the momentary forces acting on the suspensions of the frontwheel and rear wheel and to calculate the difference between this ratioand a given value. The visual display device is adapted to display thedeviation.

In one embodiment the apparatus of the invention is provided with adecelerometer means adapted to detect deceleration in the runningdirection of the motorcycle or acceleration in the opposite direction;and a calculating means adapted to calculate from the output signal ofthe decelometer means the ratio of the momentary forces acting betweenthe front and rear wheel and the ground and to calculate the differencebetween said ratio and a given value.

Preferably, the display means of the visual display device is symmetricand the extent of deviation from the given or ideal ratio is displayedlinearly. The display device may be realized in the form of an indicatorwith a pointer or a screen. For example, the diagram of braking may bedisplayed on the screen which can be used for subsequent evaluation. Thegiven value may be a calculated value or a value based on experiments,tests, for example under certain load, in state of rest or runningstate. To this end the apparatus may be provided with means for settinga basic value, for example a push-button which activates measurement andcalculation needed for determining the given value serving as the baseof comparison.

The apparatus may be used for training purposes, not only with realmotorcycles but also with stationary simulators or specialtraining-machines.

Details of the present invention will now be disclosed with reference tothe accompanying drawings showing exemplary embodiments.

FIG. 1 is a schematic drawing of a motorcycle provided with theapparatus according to the invention.

FIG. 2 shows an exemplary embodiment of the visual display deviceaccording to the invention.

FIG. 1 is a schematic drawing of a motorcycle having a front wheel 3 anda rear wheel 4 mounted to the body of the motorcycle through elasticsuspension 1,2. The wheels 3, 4 can be braked independently of eachother in the customery manner by means of a brake lever and/or brakepedal. By this, the braking force can be applied to the front wheel 3and rear wheel 4 separately. If the braking force applied to the frontwheel 3 considerably exceeds the braking force applied to the rear wheel4 the motorcycle might overturn. To be more exact, if the braking forceapplied to the front wheel reaches a certain level, when the force ofweight and the cumulated resultant vector of the inertial forceresulting from deceleration (acceleration) intersects the horizontalline correspondent to the ground at a point being out of the sectiondetermined by the contact points of the wheels and the ground, then thecentre of gravity turns round the front wheel 3 (or rear wheel 4), i.e.the motorcycle overturns in the forward (or backward) direction.

Inversely, it might happen that the motorcycle overturns in the backwarddirection for example if the driver suddenly gives full throttle, thenon-driven front wheel 3 will move away from the ground and the vehiclemay overturn in the backward direction. In order to avoid thesesituations the purpose of the arrangement according to the presentinvention is to make the degree of danger visible, perceptible duringtraining or real vehicular traffic. To this end the force applied to therear wheel 4 and front wheel 3 as well as the ratio of these forces mustbe determined. In the state of rest the ratio of these two forces ofweight is given in accordance with the mass distribution.

Forces can be measured directly or indirectly. When measurement isperformed directly a suitable sensor should be installed in thesuspension structure of the respective wheel. This sensor would measurethe compressing force applied to the elastic suspension, i.e. thepressure exerted on the ground by the wheels. This solution may involvea number of technical difficulties. It is preferable to use the indirectmethod. This latter case is examined theoretically with reference toFIG. 1.

The wheels 3,4 respectively bear the weight of the motorcycle dependingon the geometrical position of the centre of gravity, in accordance withthe static wheel-load. This is modified by the inertial force duringacceleration and deceleration. It is called dynamic wheel-load. Theforces acting on the motorcycle when the brake is operated are shown inFIG. 1. The following are supposed for determination of them:

-   -   the braking effect is instantaneous, the braking force        guaranteed by adhesion is maximal;    -   the brake is operated on a slippery road    -   air resistance, friction resistance, rolling resistance and the        effect of rotating mass are negligible.

Forces shown in FIG. 1 are the following:

F_(T) is the inertial force;

G is the force of weight resulting from the mass of the motorcycle; and

Z₁ and Z₂ are the forces developing at the meeting points of the wheelsand the ground (contact points).

By applying the equation of moment in the state of equilibrium to thecontact point of one of the wheels 3, 4, the dynamic wheel load forcesof the motorcycle, i.e. the equations determining forces Z₁ and Z₂ canbe obtained.

$Z_{1} = {{G \times \frac{l_{2}}{l}} + \frac{F_{T} \times h}{l}}$$Z_{2} = {{G \times \frac{l_{1}}{l}} + \frac{F_{T} \times h}{l}}$

Considering that

$F_{T} = {\frac{G}{g} \times a}$

In which:

g is the gravitational acceleration;

a is the deceleration of the motorcycle;

l is the axle base;

l₁ is the first portion of the axle base;

l₂ is the second portion of the axle base; and

h is the height of the centre of gravity

Axle base l is the distance between the contact points of the two wheels3,4. By vertically projecting the centre of gravity M onto the axle baseit is divided into a first portion l₁ and a second portion l₂.Naturally, the centre of gravity M is determined in relation to amotorcycle under workload. Forces Z₁ and Z₂ developing between wheels3,4 and the ground can be determined by the following formula:

$Z_{1} = {\frac{G}{l} \times \left( {l_{2} + {\frac{a}{g} \times h}} \right)}$$Z_{2} = {\frac{G}{l} \times \left( {l_{1} + {\frac{a}{g} \times h}} \right)}$

It can be seen from the equations that the moment of inertia bringsabout a significant change in wheel-load during braking. The load onfront wheel 3 increases while the load on rear wheel 4 decreases, inextreme cases it is reduced to zero. When determining Z₁/Z₂, in order toavoid dividing by zero when the ratio is calculated, a constant additivemember can be used. There is no need for use of this additive memberwhen Z₂/Z₁ is calculated because prior to turnover Z₁ can not be zero.

Because of the changes in dynamic wheel-load the motorcycle tilts in theforward direction, at this time the spring of the elastic suspension ofthe front wheel is compressed while the load on the spring of theelastic suspension of the rear wheel is reduced to zero. Compression ofthe springs is proportional to the load applied to them. The correlationbetween the most important features of a spring is determined by thecharacteristic of the spring which is constant in time in case of agiven spring, i.e. in case of a certain amount of load the spring willalways be compressed to the same extent.

It follows from the foregoing that in case of a given motorcycle forcesZ₁ and Z₂ developing at the contact points of the wheels can be definedon the basis of the movement of the spring members, consequently theinertial force, deceleration of the motorcycle can be determined.Inversely, when a is known, then the movement of the spring members canbe defined.

This is taken as the basis of the present invention. Accordingly, thedeceleration a of the motorcycle is measured by means of adecelerometer, and depending on the result of this measurement, forcesacting between the wheels 3,4 and the ground, i.e. Z₁ and Z₂ aredetermined.

The decelerometer for measuring deceleration a can be a sensor 5(FIG. 1) which is available on the market. This sensor may for exampleoutput a substantially linear signal which is proportionate to theextent of spring compression induced by the inertial mass. This outputsignal, for example voltage, is proportionate to the degree ofdeceleration. By suitable calibration the so obtained linear signal canbe used for determining the ratio of Z₁ and Z₂ values. The deviation ofthis ratio from a given value is calculated and displayed. The givenvalue can be for example the ratio of the respective forces determinedin the state of rest (under load). Experience shows that this ratio isnearly the same with motorcycles of different types having differentload. This makes it easier to take the given value into account even incase of an all-purpose apparatus according to the invention. Calibrationof the apparatus can be fined with respect to type and varying loadconditions. When the ratio calculated on the basis of the output signalof sensor 5 exceeds a given threshold, a signal may be given to thedriver. The given threshold may be determined on the basis ofexperiences or calculation. Since speed is not considered in the aboveequations, when braking is effected at low speed the same threshold canbe used for pre-signalling that the rear wheel 4 moves away from theground. An experienced driver is able to decide the safe limit beyondwhich the dangerous “lift-off” may occur.

Basically, sensor 5 for measuring deceleration may be mounted on anoptional part of the motorcycle. Preferably, it is positioned at a placenear the evaluation unit, which determines the values and the ratio offorces Z₁ and Z₂. Since this component part measures the decelerationvector component in the horizontal direction, this must be taken intoaccount and it must be fixed in the proper direction. Advantageously,sensor 5 is placed so that it is protected from external effects.

An evaluation unit (not shown in FIG. 1) is added to the signalcorrespondent to deceleration. This evaluation unit provides a drivesignal to the visual display device 7. Further, the evaluation unitcalculates values Z₁, Z₂, Z₁/Z₂ according to the formulas describedearlier. To this it can be provided with a microprocessor or a simplecircuit adapted to perform electronic calculations.

To display the threshold values the drive signal of the evaluation unitwhich actuates the visual display device 7 must be assigned to thethreshold values so that the visual warning information can be displayedbefore the rear wheel 4 moves away from the ground. Advantageously, thethreshold value can be adjusted for example by means of an adjustingknob or any other suitable means.

An evaluation means adapted to measure the deceleration through thechanges in speed (revolution) can also be mounted on one of the wheels,preferably on the front wheel 3 of the motorcycle. However, in case of asimple design for example which is adapted to measure the time of acomplete revolution and count these revolutions, measuring ofdeceleration is less reliable than in case of a separately placedsensor. It is more accurate if the angle change is measured at severalpoints during a revolution. In this case the speed of rotation is knownfrom the degree of the angle change of the mechanical or inductivesensor means relative to a given point on the wheel. In the simplestcase it is a complete revolution. This, however, results in thatinformation can be obtained only after a complete or a certain partialrevolution. This would render only delayed evaluation possible. If theangle change is measured at several points of number n per revolution,the delay time will be the time needed for the wheel to travel adistance corresponding to the n-th part of the wheel's perimeter. Inorder to display the danger of an immediate rise of rear wheel 4 and themotorcycle's turnover in time and with high accuracy, this solutionworks satisfactorily if n>1. With this solution a further embodiment maybe accomplished, wherein measuring of speed is derived from the numberof revolutions. The value of deceleration is calculated from the changein the revolution number.

This arrangement can be used as means for measuring the braking distanceduring braking and displaying it on visual display device 7. To this asensor coupled to either front wheel 3 or rear wheel 4 for counting therevolutions can be used. If this sensor is coupled to the driven rearwheel 4 it may be installed in the driving chain, the main point is thatit must be able to count the revolutions e.g. during braking. Accordingto this embodiment the decelerometer means is a revolution counter meanscoupled to the front wheel 3 or rear wheel 4 or gearbox or driving chainof the motorcycle. Deceleration (acceleration) can be calculated fromthe time changes in the peripheral speed of the relative wheel by meansof a calculating means. This calculating means must be added to therevolution counter means.

Induction-coupled means for counting the revolutions also can be used.

Further, it is possible to use two decelerometers of different typeswith the same motorcycle. In this manner a single motorcycle may beprovided with both sensor 5 and revolution counter means.

An additional sensor 6 may be used for sensing the lift-off of the rearwheel 4. This can be a force-meter which—in addition to performing thecalculations mentioned before in order to give notice of the impendinglift-off—is adapted to sense the actual moment of lift-off if it shouldhappen. By measuring deceleration a the event when the wheel's lift-offis not caused by travelling on a rough ground surface but because ofbraking, can be filtered out. Sensor 6 may be installed for example inthe support of the suspension spring or somewhere else where it does notdisturb the functioning of the elastic suspension system 2. If wheel 4rises off the ground the value of this force will be zero. In aparticular case sensor 6 may be a decelerometer or an accelerometerwhich detects the lift-off on the basis of acceleration in the verticaldirection. The aforementioned momentary forces may be measured directlyor indirectly. In case of direct measurement (which may correspond tothe arrangement shown in FIG. 1 without sensor 5) a sensor 6 isinstalled in the elastic suspension 2 of wheel 4. This sensor 6 measuresthe compressing force applied to the spring. Sensor 6 may be installedfor example in the support of the suspension spring or somewhere elsewhere it does not disturb the functioning of the elastic suspensionsystem 2. It is to be noted that a similar means may be used with frontwheel 3 (this is not shown in the Figures). If wheel 4 rises off theground the value of this force will be zero. To avoid dividing by zerowhen the ratio is calculated, this value can be increased by a constantadditive member. The same is true for the force measured and calculatedfor the other wheel.

Force may also be measured indirectly (without measuring decelerationand calculating ratio). The basis of this measurement is that theelastic suspension 1 moves against the spring force relative to themembers fixedly mounted on the motorcycle's body. Accordingly, wheel 3or the axle of wheel 3 can move along a given straight line. The extentof displacement corresponds to the spring force of elastic suspension 1.In this manner force measurement is derived from distance measurement.Distance measurement can be carried out by using any known sensor meanse.g. magnetic, optical or induction means.

In this manner sensors 5, 6 directly or indirectly provide an outputsignal proportionate to the amount of force applied to wheels 3,4. Thesesignals are used for calculating the ratio of the momentary forcesacting on the respective suspensions 1, 2 of front wheel 3 and rearwheel 4 and the difference between this ratio and a given value isobserved continuously. To this a suitable calculating means is used forexample a simple analogue or digital circuit. The output signal of thecalculating means is transmitted to a visual display device 7 which isadapted to display the deviation.

The given value or basic value can be the ratio of the forces acting onrespective suspensions 1 and 2 of front wheel 3 and rear wheel 4 in thestate of rest. This value as well as the ratio calculated from theoutput signal of the sensors is a non-dimensional ratio. The apparatusaccording to the invention is designed for displaying the differencebetween these non-dimensional values. In an advantageous embodiment thedifference is displayed along a line the central point of which denotesthe state of rest, i.e. when the difference is zero. Negative andpositive deviations from this value can be displayed along the line intwo different directions. Such display device can be seen in FIG. 2.Here, the display device comprises LED means 13 arranged in a line. Whenthe ratio of forces acting on the front wheel and rear wheel equals tothe ratio calculated in the state of rest, the LED in the centre line 10is lighted. In the embodiment shown in FIG. 2 in order to make it moreperceptible two LEDs one above the other are positioned in the centreline 10. In the event that the danger of turnover exists the forceapplied to the rear wheel 4 significantly decreases relative to theforce applied to the front wheel 3. In this case a LED 13 or severalLEDs 13 in the respective direction along the line start flashing inthis manner the driver of the motorcycle is informed of the danger. Thecritical values can be marked by lines 11 and 12 (safe limits) and/or bychanging the colour and/or the light intensity of the LEDs. The safelimits may be determined depending on the type of the motorcycle.

A display device of another type, for example a conventional indicatormeans having a pointer may also be used as visual display device 7 fordisplaying deviations. The indicator may have a real pointer or anoptical representation of the same. In this case a screen may be used asvisual display device 7. The advantage of using a screen is that inaddition to displaying the pointer of the indicator, other symbolsvisualizing the deviation may also be displayed in order to warn thedriver. A diagram may be displayed which shows the duration ofacceleration or deceleration in addition to showing the deviation fromthe given value. Further, alphanumeric display of the length of brakepath is also possible. This additional information may be instrumentalin learning to drive a motorcycle. A further possibility is to give anacoustic signal for example when the given threshold is reached. Theintensity or other characteristic feature of the acoustic signal maydepend on the extent of deviation.

With any of the aforementioned display device it is preferable todisplay the positive and negative values of deviation in two directions(symmetrically). It is shown in FIG. 2.

The main object of the apparatus according to the invention is toprovide appreciable information for the learners or the drivers of themotorcycle which can be compared to their own experiences in order tomake use of it during learning or in traffic. To this, the condition ofactivating the display may be that either the front wheel brake or therear wheel brake is being operated. However, a solution is feasible thatsome sort of signal is displayed on the visual display device withoutoperating the brake, but this does not deviate from the centre position.

The given value referred to above (the number used for comparing theratio of the momentary forces acting on wheels 3 and 4) may bedetermined by means of sensors 5, 6 at a selected point of time in adesired state. (E.g. The weight distribution between the front wheel 3and rear wheel 4 depends on whether only a driver rides on a driver'sseat or a passenger also rides on a pillion.) The apparatus may beprovided with means for setting a basic value, for example a push-buttonwhich activates measurement and calculation needed for determining thegiven value. This may be done either in the state of rest or runningstate. When the push-button is operated, the apparatus according to theinvention measures the forces applied to wheels 3,4, calculates theratio of them (by adding a constant in advance if needed) and this basicvalue will serve as the basis of comparison during display. The givenvalue remains unchanged until a new basic value is set. The push-button(means for setting the basic value) may be mounted on an optional partof the motorcycle where it can be controlled easily.

Further, it is possible for the display device to display otherinformation relating to travel, e.g. brake path, acceleration, speed,etc. Further, the display device 7 may be adapted to real-time displayof the current optimal brake path associated with the actual speed.Optimal brake path means the shortest brake path needed for stopping themotorcycle in case of evenly applied brake force so that it does notresult in turnover. In another case, when the purpose is to promotelearning to drive a motorcycle the braking distance can be displayed onthe basis of a limit value set differently from the ideal one.

In certain situations during travel the force applied to the wheels mayvary significantly for a short time due to the road conditions forexample. Advantageously, the signal of the sensor is transmitted througha filter which filters out the changes which are of shorter durationthan a given threshold value, and makes the output signal more even.This given threshold value may be approximately 0-1 sec. Advantageously,this threshold value can be altered by setting the parameters of thefilter. In this manner the apparatus works properly under different roadconditions.

Each of the foregoing embodiments of the apparatus according to theinvention relates to a real motorcycle running on a real road. However,there are cases when simulation of the effect of operating the brakes iswished especially for the purpose of teaching. To this end the apparatusmay have a mode of operation in which the output signals of the sensorsare simulated. A signal proportionate to the amount of force applied byoperating the brake lever or brake pedal may be produced. In this mannerthe degree of danger can be displayed even in case of a fixed (notmoving) motorcycle, there is no risk involved. An apparatus of this kindcan be adapted to a real motorcycle e.g. so that when it is switched tosimulation mode of operation the running situations mentioned earliercan be established even if the motorcycle moves slowly or not at all. Onthe other hand, it is possible to construct specific body frames forsimulation purposes which can be used for practising the use of thebrakes. Naturally, in this case further signalling elements must beadded to the simulator, e.g. speedometer.

1-17. (canceled)
 18. Visual information apparatus for real-timedemonstration of braking behaviour of a motorcycle, the motorcycle isprovided with elastically suspended front wheel and rear wheel (3,4),independently operable front wheel brake and independently operable rearwheel brake and a visual display device (7) said apparatus is providedwith sensors (5,6) adapted to measure directly or indirectly themomentary forces acting on said elastic suspensions (1,2) of the frontwheel and rear wheel (3,4) respectively, or to measure indirectly theratio of said momentary forces; characterized in that a calculatingmeans adapted to calculate from the signals of said sensors (5,6) theratio of said momentary forces acting on said suspensions (1,2) of saidfront and rear wheel (3,4) and to calculate the difference between saidratio and a given value; the visual display device (7) is adapted toreal-time display of said deviation and the current optimal brake pathassociated with the actual speed.
 19. Visual information apparatusaccording to claim 18 characterized in that for indirect measurement ofsaid forces said apparatus is provided with a decelerometer meansadapted to detect deceleration (a) in the substantially horizontalrunning direction of the motorcycle or acceleration in the oppositedirection; and a calculating means adapted to calculate from the outputsignal of said decelometer means the ratio of the momentary forces(Z₁,Z₂) acting between said front and rear wheel (3,4) and the groundand to calculate the difference between said ratio and a given value;and said visual display device (7) is adapted to display the deviation.20. Visual information apparatus according to claim 18 characterized inthat said decelerometer means is a sensor (5) applicable to measuredeceleration.
 21. Visual information apparatus according to claim 18characterized in that said given value is the ratio of forces acting onsaid elastic suspensions (1,2) of said front wheel and rear wheel (3,4)in the state of rest.
 22. Visual information apparatus according toclaim 18 characterized in that said visual display device (7) is adaptedto display the positive and negative values of deviation by displayingflash signals in two directions.
 23. Visual information apparatusaccording to claim 22 characterized in that said visual display device(7) contains LED means (13) arranged in a line.
 24. Visual informationapparatus according to claim 22 characterized in that said visualdisplay device (7) is an indicator means having a pointer.
 25. Visualinformation apparatus according to claim 22 characterized in that saidvisual display device (7) is a screen.
 26. Visual information apparatusaccording to claim 18 characterized in that said visual display device(7) is active only when one of the brakes is operated.
 27. Visualinformation apparatus according to claim 18 characterized in that it isprovided with means applicable to give acoustic signals depending on thevalue of said difference.
 28. Visual information apparatus according toclaim 18 characterized in that it has a mode of operation for simulatingthe signal of said sensor (5).
 29. Visual information apparatusaccording to claim 18 characterized in that said given value is theratio of the forces acting on said elastic suspensions (1,2) of saidfront wheel and rear wheel (3,4) measured under a given loaddistribution at a selected point of time.
 30. Visual informationapparatus according to claim 18 characterized in that the signal of saidsensor (5,6) is transmitted through a filter adapted to average thechanges which are of shorter duration than a given threshold value. 31.Visual information apparatus according to claim 30 characterized in thatsaid given threshold value can be set optionally, e.g. 0.1 sec. 32.Visual information apparatus according to claim 29 characterized in thatfor determination of said given value the apparatus is further providedwith means for setting a basic value which is adapted to activate themeasurement with said sensors (5,6) and the calculation of said givenvalue with said calculating means at said selected point of time. 33.Visual information apparatus according to claim 18 characterized in thatsaid decelerometer means is a revolution counter means coupled to saidfront wheel (3) or rear wheel (4) or gearbox or driving chain of themotorcycle and it is provided with an additional calculating means forcalculating the time changes in the peripheral speed of the relativewheel.
 34. Visual information apparatus according to claim 18characterized in that it is provided with sensors (5,6) adapted tomeasure indirectly the momentary forces acting on said elasticsuspensions (1,2) of the front wheel and/or rear wheel (3,4) on thebasis of the position of the respective wheel (3,4).